Electrical switches



March 11, 1958 A, GREASLEY 2,826,653

ELECTRICAL SWITCHES Filed May 10, 1956 FIG. 2;

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United States Patent ELECTRICAL SWITCHES Eric Arthur Greasley, Stapleford, England, assignor to Cinch Manufacturing Corporation, Chicago, 111., a cor poration of Illinois Application May 10, 1956, Serial No. 584,131

Claims priority, application Great Britain May 13, 1955 10 Claims. (Cl. 200-5114) This invention relates to electrical switches and it is an object of the invention to provide an improved form of switch incorporating a warning light to indicate when the switch is closed.

According to the present invention an electrical switch and lamp unit comprising a housing formed of insulating material and provided with spaced switch contacts and a lamp bulb engaging contact, a metal lamp holder having means for electrically engaging a contact of a lamp bulb being mounted in said housing so as to be adjustable relatively thereto into and out of bridging engagement with said switch contacts and simultaneously control the circuit connections to the lamp bulb contacts so that they will be closed when the switch contacts are bridged.

To enable the invention to be fully understood it will now be described with reference to the accompanying drawing, in which:

Fig. 1 is a sectional side view of a switch, and lamp unit according to one embodiment of the invention, an

Fig. 2 is a plan view thereof.

As shown in the accompanying drawing a housing 1 is provided comprising a tubular member formed of insulating material which is secured by a nut 2 to a base 3. At its lower end the housing is formed with a lateral flange 4 to which an end plate 5 is secured by rivets 6. The rivets also. serve to secure electrical contacts 7 and terminal wiring contacts 8 to the housing. As shown the contacts 7 include portions extending through holes 9 in the end plate 5 and end portions consisting of resilient contact strips or blades 10 which extend inwardly of the housing in spaced parallel relation to form switch means.

Centrally of the contact blades 10 there is provided a plunger 11 which extends through a hole in the end plate and is resiliently supported on the latter by a spring 12. The plunger is adapted to form an earth contact for engagement with the base contact 22 of an inserted lamp bulb 13. As shown the plunger 11 is slidable in a metal tube 11a which is secured in a hole in the end plate 5 and has a wiring tag 14 connected to the portion disposed on the underside of the end plate. The plunger 11 is normally urged by the spring 12 into engagement with the base contact 22. The tube 11a acts as a guide and support for the plunger 11 and serves to prevent its lateral displacement.

The housing 1 is adapted to support a casing formed of insulating material and including a sleeve portion 15 which is rotatably mounted in the housing. The casing is formed of transprent synthetic plastic material and includes a lens or hood portion 16 and a transversely extending rib 17 which forms a finger grip for retaining the sleeve. A lamp holder 18 is adjustably mounted in the sleeve 15 and comprises a tubular metal shell which is capable of rotational and sliding movement within the sleeve. The shell is open at its lower end and its upper end is provided with a lamp receiving opening the edges of which are shaped in known manner to provide nut means 19 for screw engagement with the screw threaded base 13a of the lamp bulb.

A stud 20 projects radially outwards of the side wall of the shell 18 and extends into a helical slot 21 formed in the sleeve 15.

The unit is particularly adapted for mounting on the dashboard of a motor vehicle and in practice assuming that an earth returning system is used the terminal 14 will be earthed and terminals 8 connected in circuit with the car battery and a reversing light or other electrical component to be controlled by the switch means comprised by the contact blades 10. When it is desired to close the circuit to the reversing light or other component the sleeve 15 is rotated by manipulation of the finger grip and by virtue of the helical groove 21 and stud 20 a rotational and longitudinal movement is imparted to the shell 18 inwardly of the housing to bring the lower end of the wall of the shell into wiping contact with the blades 10 so that the latter are bridged and the switch means closed. As the base contact 22 of the lamp bulb is permanently positioned in engagement with the plunger 11 the circuit connection to the lamp is simultaneously completed through the engagement of the nut means on the shell already in electrical engagement with the side wall of the lamp base which side wall constitutes the other contact of the lamp bulb. Accordingly the closing of the switch means 10 will simultaneously close the circuit to the lamp which will provide an indication or warning that the circuit to the electrical component connected to the switch means is closed and will serve as a reminder should the switch means be inadvertently left closed.

By rotating the sleeve 15 in a reverse direction the shell will be moved in an opposite direction out of bridging engagement with the switch means 10 so that the circuit to the electrical component and the circuit to the lamp bulb will be simultaneously opened.

It will be noted that the sleeve 15 is prevented from partaking of longitudinal movement relatively to the housing by the annular flange 23 engaging a shoulder 24 on the inner wall of the housing and the outwardly extending flange, adjacent to the finger grip, overlapping the upper end of the housing.

It will be understood that if an earth. return wiring system is not used the electrical connection to the terminals 8 and 14 will be suitably modified. For example, the lamp bulb holder could be provided with spaced contacts engageable with the respective contacts of the lamp and adapted to be connected to the respective blade contacts 10 when the latter are bridged to close the switch means.

Although the unit is particularly adapted for mounting on the dashboard of a motor vehicle so that the lamp provides an indication or warning that a particular electrical component such as a reversing light, has been switched on, it is not limited to this use.

I claim:

1. An electrical switch and lamp unit comprising a housing formed of insulating material and provided with spaced switch contacts and a lamp bulb engaging contact, a metal lamp holder having means for electrically engaging a contact of a lamp bulb being mounted in said housing so as to be adjustable relatively to the housing into and out of bridging engagement with said switch contacts and simultaneously control the circuit connections to the lamp bulb contacts so that they will be closed when the switch contacts are bridged.

2. A switch and lamp unit according to claim 1 wherein the holder is supported in a sleeve rotatably mounted in the housing, the sleeve and holder having a pin and slot connection so that rotation of the sleeve imparts a longitudinal sliding movement to the holder relatively to the Patented Mar. 11, 1958 housing to move it towards or away from said switch i contacts.

3. A switch and lamp unit according to claim 2 wherein the sleeve is provided with a finger grip disposed outwardly of the housing for effecting the said rotational movement. I

4. A switch and lamp unit according to claim 3 wherein the sleeve is provided with a lens or hood portion adapted to extend over the bulb of an inserted lamp.

5. vA switch and lamp unit according to claim 4 wherein the sleeve or lens and hood are integrally moulded from transparent synthetic plastic material.

6. A switch and lamp unit according to claim 2 wherein the pin and slot means comprises a helical groove in the sleeve engageable by a laterally projecting stud on the holder.

-7. A switch and lamp unit according to claim 1 wherein the holder comprises a tubular metal shell having a lamp bulb receiving opening in its upper end, the edges of the opening being shaped to provide means for screwing engagement with a screw threaded ease of a lamp bulb, the diameter of the shell being such that when the holder is moved inwardly of the housing the lower end of the shell will engage and bridge said switch contacts.

8. A switch and lamp unit according to claim 7 wherein the lower end of the shell is open to permit a spring urged plunger forming a lamp engaging contact to extend into the shell for engagement 4 with the base of an inserted lamp bulb.

9. An electrical switch and lamp unit comprising a housing formed of insulating material in which a metal holder carrying an electrical lamp bulb is adjustably mounted, the holder being electrically connected to a side wall contact of the lamp bulb, the housing being provided with switch means and a contact in engagement with a base contact of the lamp bulb, rotatable means being provided and connected with said holder in such a manner that rotation of said means in one direction will elTect a longitudinal movement to the holder to a position to effect the closing of said switch means and simultaneously close the circuit to the lamp bulb, and on rotation in an opposite direction will efiect the opening of the switch means and simultaneously open the circuit to the lamp bulb.

10. An electrical switch and lamp unit according to claim '9 wherein the lamp base engaging contact comprises a plunger slidable in a tubular guide and normally urged by a spring into engagement with the base contact of the lamp.

References Cited in the file of this patent UNITED STATES PATENTS 2,146,011 Dame Feb. 7, 1939 

